US 129 was there in the beginning, though it was a relatively short Georgia intra-state route (meeting its parent route, US 29, in Athens). In Macon, US 129 came into town on North Avenue, and then Spring Street down to Mulberry Street. It is possible that US 129 junctioned with US 41 and/or US 80 at that intersection (this map is not clear about intra-city routings):

c. 1931, Gousha

Regardless, given highway signage practices during that time period, it is almost certain that US 129 would have extended east on Mulberry, ending at the courthouse on 2nd Street. This interactive image is looking west on Mulberry, which was northbound US 41 and westbound US 80. It is uncertain whether one or both routes continued straight ahead on Mulberry, or angled to the left via Cotton Avenue. But it is very probable that the south beginning of US 129 was straight ahead on Mulberry (pan right to see the courthouse):

In Gainesville at the time, it was US 19 (not US 23) that ran through town. The north end of US 129 was at its junction with US 19:

c. 1930, GA DoT

In those days, neither E.E. Butler Parkway nor Jesse Jewell Parkway had been built yet. Rather, historic maps indicate that US 19 used Spring Street through town, and that US 129 came in on Athens Highway and Green Street. This image is looking south on Green:

The cross street is Spring; straight ahead on Green is now closed to vehicles, but that was the original north beginning of US 129.

In 1931, US 19 was rerouted such that it bypassed Gainesville, instead passing through Dahlonega and Dawsonville. The US 23 designation was extended into Georgia, carrying traffic through Gainesville. US 129 was extended north along the former US 19 through Cleveland. It ended at its junction with US 19 northwest of town, at an intersection known as Turners Corner:

c. 1932, GA DoT

This image is looking north on US 129. To the left is southbound US 19, and northbound is straight ahead. Today US 129 continued ahead with US 19, but during the early 1930s, this was the north end of US 129:

That terminus did not last for long, either: in 1935 the north end of US 129 was extended to Knoxville. Before it had been routed onto the modern four-lane between Knoxville and Maryville, US 129 ran along what is now TN secondary hwy. 33, or the Maryville Pike. At Chapman Highway/Henley Street (which is now US 441), traffic was directed north into downtown Knoxville, ending either at Main Street or Cumberland Avenue (depending which historic maps were correct). This one indicates that US 11-70 remained on Cumberland...

c. 1938, TN DoT

...but this one shows that traffic veered onto Main to connect with Henley:

c. 1942, USGS

This shot was taken from a vantage point between Main and Cumberland, looking north on Henley. Today northbound US 11 and eastbound US 70 come in from the left on one-way Main Street (one block behind the camera), and are then routed north here onto Henley, along with US 441. But there was no US 441 here at the time when US 129 ended here:

Karners, Apr. 2014

In 1941 the south end of US 129 was extended to US 41 at Jasper:

c. 1946, FDoT

This shot was looking west on northbound US 41-129:

Nasiatka, July 2008

​Today US 129 splits off to the right, but for a few years that was the south beginning of US 129.

Then in 1948 the designation was extended further south: behind the camera for a short distance, then through Live Oak to Branford. From there, US 129 followed what is now FL hwy. 349 to Old Town, ending at its junction with US 19:

c. 1949, FDoT

This shot was looking east on US 98, which is also southbound US 19-27A:

Nitzman, July 2007

​In 1948 that was only US 19, and for about the next decade, the south beginning of US 129 was to the left on today's FL 349.

Then in 1959, US 129 was rerouted along its present course south of Branford, ending at its current terminus in Chiefland. Meanwhile, its former corridor between Branford and Old Town was designated Alt. US 129:

c. 1960, FDoT

Here are a couple views looking northwest on Young Boulevard (or northbound Alt. US 27 as well as US 19-98, which joined this road just behind the camera:

Summa, 1978

Cozart, Dec. 2003

Almost all colored shields in Florida have long since been replaced. US 129 begins to the right on Rodgers Boulevard; here is a view from the opposite direction...

Nitzman, Jan. 2006

...and for drivers who turn to the north there, the first confirming assembly looks like this:

Nitzman, Jan. 2006

Heading the opposite direction, there was no "End" sign, but this assembly was posted at US 129's south terminus. The green sign in the distance points left to Inglis, Cedar Key, and St. Petersburg; and Fanning Springs to the right.

Nitzman, Jan. 2006

Back to the north end of US 129 in Knoxville: in about 1960, traffic was routed onto the Alcoa Highway, ending at its interchange with I-40. This was the northernmost trailblazer:

Patriarca, summer 2003

Just ahead, there was no "End" signage where US 129 terminates at I-40's interchange 386B:

Sanderson, Oct. 2000

Patriarca, summer 2003

Heading out of downtown Knoxville on westbound I-40, the signs shown here mark the exit to the north beginning of US 129:

Sanderson, Oct. 2000

Patriarca, summer 2003

Here is the signage from the opposite direction (eastbound I-40), and drivers taking that exit soon see the first US 129 confirming assembly:

Patriarca, summer 2003

Ivy/Nitzman, 2009

Ahead, US 129 serves the Knoxville airport, which is actually closer to Maryville. South of Maryville, 129 heads into the hills and skirts the south edge of Great Smoky Mountains National Park. It is a winding road, and 40 mph is about the most travelers can do in many places.